We made the choice approx 4 years ago to use a wood pellet system. I like it as the unit I have sits in my sun room so is a feature as well. I use it to heat a 350l thermal store which from it the water for my UFH system is drawn. As its a thermal store and I have good water pressure coming to the house I have 2 really powerful showers.
I also have a wood burner stove in the living room. I cleared approx 35-40 trees from the boundary of my site so have plenty of wood to burn for a good few years. It's not connected to the heating system. To get all the grants from the rhi scheme the pellet system has to be my only method of heating water.
I also divert excess PV to heat the water for near enough 5-6 months of the year.

We currently have wood pellets in our rented place heating a thermal store also for hot water and radiators.....I do like them but they have not came down in price etc and still circa £225/ ton in small bags delivered. Also don't think there are any incentives or grant payments for them now? So was not considering them in new build.

When you say you divert PV ..what do you mean? Does this happen automatically for the immersion to heat water for the thermal store? - seems large volume to tend to? Is this effective or is there an intermediate storage for this hot water? Etc ...apologies I have limited plumbing knowledge so talk simple ! Lol

The price has been pretty steady this last few years which is a positive for me. Always free delivery offers or £10+ discount codes available.
My PV uses a system called iboost to divert any excess generation to heat my water tank. There are a few different brands but they all do the same thing. Your PV will generate electricity when the sun shines. If your house has a demand for this it will use it. If there is no demand or excess left over instead of selling it back to the grid you divert it to your immersion so it heats the water. Iys done all automatically so its always working away in the background. Very good system that even here it will provide hot water from april to October.
Today was really good and at the minute I have generated 20.4 kW. My iboost has used 16.5kw to heat the water. The rest I either used and maybe even sold back some.
If your looking at PV then this type of system is an easy and cheap way to go e you hot water. Think it was only £200 extra so not a lot.

Yep cracking day touching 18degrees here near omagh....PV would be good these days for sure..Have u 16 panel setup?
does your 16kw have big impact on 350 liters of water ? Must be clever control systems to figure the thermall store inputs
!
In our climate, Would u have many months like this where enuf electric is got to cover e r demand and heat all stored water to temp ...presume it goes to grid for selling cheaply to Mr Nie? Cheers T

I have a 4kw system so its 14 panels of 280w each.
There is a monitor you clip on to a cable in your meter box. When it detects you sending electric back to the grid it sends a signal to the iboost which turns on your immersion. A day like today it would have been on near all day. A cloudy dull day it would be on off all day so might not heat it all up but still good for a shower or 2 doubtful for a bath.
Last year from late April to October I had more than enough hot water except for maybe an odd day. If you had maybe 2-3 really bad days with no generation then the tank would cool down from its standing losses.
The tarrif I got was when it was higher. When I sell 1 kW back I get 5.4p so makes more sense to heat the water.

Worth pointing out that PV generates when there is light, it is just the amount that varies with intensity.
Also worth noting that electricity takes the shortest path, so even if you have a load that is greater than your generation, it reduces imports (3kW kettle on, PV churning out 2kW, import reduced to 1 kW).
Therefore most if your export is done at times you are not consuming much, but the days are long.

There is also the temperature and module angle quirk in the summer.
As modules get warmer, they produce less for any given radiation input. This generally does not cause much of a problem as the solar intensity can be over the rating of the module (say it gives 250Wp at 1000W.m-2 it may wel1 still give 250W if there is 1100W.m-2 even if the module is warmer).
The bigger difference may be caused by the angle of the module. If it is set up for maximum annual yield, it is not idea for the summer months and you can loose some kWhs.

The main thing to remember is that they only produce what they produce, so it is easier to adjust lifestyle i.e. learn what is likely to be produced and work with it.